This invention relates to power control circuitry and, more particularly, to an improved push switch and potentiometer assembly therefor.
In conventional power control devices, such as for example, dimming devices for lighting systems or motor speed controls, power control may be achieved by controlling the conduction time of a switching device, commonly referred to as phase control of power. This conduction time is controlled through the use of a potentiometer which is part of the power control circuit connected between the power source and the load. Typical prior art systems have utilized a circular potentiometer enclosed in a relatively bulky housing. The bulkiness of the housing leads to the undesirable result that a significant amount of space is required for mounting the power control unit. Additionally, the added weight of the potentiometer housing leads to increased manufacturing and shipping costs.
One type of power control device utilizes a push switch wherein the switch portion is opened and closed alternately on successive pushes of the control member. Such a switch may be fairly complex mechanically, having a plurality of cams and springs, especially when such a switch is adapted for use as a three-way switch. Additionally, the switch mechanism in such a device is typically behind the control member, adding bulk to the device.
It is therefore an object of the present invention to provide a push switch and potentiometer assembly.
It is a further object of the present invention to provide such an assembly which is compact in size and light weight.
It is another object of the present invention to provide such an assembly of simple construction.
It is yet another object of the present invention to provide such an assembly which may function as a three-way switch.
It is another object to provide such an assembly that the potentiometer resistance is near infinity when the suitable contacts open or close reducing arcing to a negligable level and thusly extending the life of the switch contacts.
Another object of the invention is to provide a push switch and potentiometer assembly having a one piece shaft and rotor facilitating the use of plastic materials by reducing the strength requirements.
Another object of the invention is to provide a push switch and potentiometer assembly especially adapted for use in light dimmers.